Feed bar for fountain pens



Oct. 6, 1970 O I 3,532,436

FEED BAR FOR FOUNTAIN PENS Filed Dec. L, 1967 v 2 Sheets-Sheet l Oct. 6,1970 F, O K; 3,532,436

FEED BAR FOR FOUNTAIN PENS Filed Dec. 196'! 2 She e tsSheet 2 Fig.7

United States Patent 3,532,436 FEED BAR FOR FOUNTAIN PENS Fritz Kiinig,Quickborn, Germany, assignor to Montblanc-Simplo GmbH, Hamburg, GermanyFiled Dec. 4, 1967, Ser. No. 687,778 Claims priority, applicationGermany, Dec. 10, 1966, M 71,975 Int. Cl. B43k /18 US. Cl. 401-227 6Claims ABSTRACT OF THE DISCLOSURE An ink reservoir and a fountain penfront portion with a nib and feed bar in a single integral unitarymember having a feed control channel. A longitudinal capillary grooveconnects the feed control channel to the underside of the nib. Inkpockets are formed by fins separated by capillary slots. An air channelincluding an inner section, a middle section and an outer sectionestablishes communication between the feed control channel and inkpockets. The middle section extends underneath fins axi ally throughoutthe entire length of the pocket arrange! ment diametrically opposite thelongitudinal capillary groove. The outer section of the air channel is abore communicating with the outside and radially offset from the middlesection. The inner end of this bore is covered by one of the fins facingthe bore in close juxtaposition thereto and creating a kind oflabyrinth. The feed bar also is provided with semicylindrical capillarygap means establishing communication between the ink pockets and thelongiudinal capillary groove.

The invention relates to a feed bar for fountain pens containing a feedcontrol channel from the ink reservoir for conveying air and ink inopposite directions, a longitudinal capillary groove connecting the feedcontrol channel to the underside of the nib, an assembly of ink pocketsformed by capillary slots separated by fins and communicating with thelongitudinal capillary groove, and an air channel leading to the feedcontrol channel.

The object of the present invention is the provision of an ink feed barwhich by virtue of a combination of features of which some areindividually known makes the fountain pen particularly safe againstspillage of ink when shaken and in practice prevents ink from beingdischarged axially even when the pen is subjected to violent impactshock.

It is another object of the invention to provide a particularly simpleand cheap form of construction which will facilitate the assembly andalso will permit the nib of the pen to be subsequently exchanged bypeople who are not highly skilled.

These and other objects and advantages of the invention will appear moreclearly from the following specification in connection with theaccompanying drawings, in which:

FIG. 1 shows on an enlarged scale an axial section of the front end of afountain pen according to the invention;

FIG. .2 is a top view of the end of the pen in FIG. 1 carrying the nib;

FIG. 3 is a cross section taken on the line III-III in FIG. 1;

FIG. 4 is an axial section of the feed bar in the fountain pen accordingto FIG. 1;

3,532,436 Patented Oct. 6, 1970 FIG. 5 is a view of the feed bar fromabove;

FIG. 6 is a cross section taken on the line VI-VI in FIG. 4;

FIG. 7 is a section taken on the line VII-VII in FIG. 4;

FIG. 8 is a section taken on the line VIIIVIII in FIG. 4;

FIG. 9 is a section taken on the line IXD( in FIG. 4;

FIG. 10 is a section taken on the line X-X in FIG. 1.

The feed bar according to the present invention is characterizedprimarily in that the air channel comprises an inner, a middle and anouter section, and that the inner section of said air channel leads fromthe feed control channel to the inner end of the ink pocket chamberwhile the middle section of said air channel extends tinderneath fins ofdiminishing height axially through the entire ink pocket chamberdiametrically opposite the longitudinal capillary groove, whereas theouter section of said air channel is a bore which communicates with theoutside and which is radially offset from the middle section, the innerend of said bore being covered by a fin facing the bore in closejuxtaposition thereto and creating a kind of labyrinth while the inkpocket chamber communicates throughout its length with the longitudinalcapillary groove through a semicyclindrical capillary gap.

The outstanding safety characteristics of a fountain pen fitted with theproposed feed bar, which prevents ink from being discharged when the penis shaken, stems from the provision of the longitudinal capillary groovewhich is covered along its entire length, and from the creation of acompletely separate path for the air, as well as from the presence of atransverse baflle in the air channel. These arrangements do not in anyway impair the ability of the ink pocket assemblly to retain and yieldink since the ink pocket chamber communicates via a semicylindricalcapillary gap with the longitudinal capillary groove and is sufficientlywell vented.

Preferably the feed bar may be of integral construction and directlyenclosed by the front part of the fountain pen carrying the nib, theelastic beak of the feed bar containing the longitudinal capillarygroove projecting beyond the ink pocket assembly and being elasticallybiased to bear through an opening in the front part of the fountain penagainst the underside of the nib. Another feature of the invention whichfurther enhances the spilling safety of the fountain pen consists inthat the feed control channel is a transverse channel in the shaftportion of the feed bar, extending peripherally from the inner sectionof the air channel to the longitudinal capillary groove.

Referring now to the drawings in detail, FIG. 1 shows on an enlargedscale the forward end 1 of a fountain pen which contains a fullyenclosed single-part feed bar comprising a feed bar shaft 2, tongue orbeak 12 and stud or heel 15. A longitudinal capillary groove 5 throughwhich ink is conveyed from the reservoir 20 to the nib extends along thelength of the feed bar from a feed control channel 4 to the nib 3 whichis fitted into the forward end 1 of the fountain pen.

Adjacent to, and in horizontal position of the pen, below the feed barshaft 2, is an assembly of ink pockets formed by transverse capillaryslots 6 between -fins 7. This ink pocket assembly communicates through asemicylin- 3 drical capillary gap 8 in the forward part of the pen withthe longitudinal capillary groove 5.

The ink pocket assembly and the feed control channel 4 are vented by anair channel comprising an inner, a middle and an outer section. Theouter section is formed in the front part 1 of the pen by an axial bore11 which is covered at its inner end by a relatively closely juxtaposedfin on the feed bar forming a baffie. The middle section 9 of the airchannel extends through the entire length of the ink pocket assemblybelow fins 7 of diminishing length. The inner end of the middle section9 of the air channel communicates through a channel 24 in the feed barshaft 2 with the feed control channel 4.

The feed control channel 4 through which air and ink can pass inopposite directions extends peripherally around the feed bar shaft 2(FIG. 5) and enters the longitudinal capillary groove 5 directlyadjacent the fitting flange 13 of the feed bar. From the feed controlchannel, the longitudinal capillary groove 5 as well as two parallellateral capillaries 16 and an air channel 17 lead in an arcuate pathinto the ink reservoir proper.

The ink reservoir 20 is screwed at into the front part of the pen fromthe back. The peripheral flange 18 which bears against a shoulder 22, inthe front part 1 of the pen and an interposed washer 19 provide areliable seal to the outside and exactly align the feed bar inside thefront part 1 of the pen.

At the forward end of the front part 1 of the pen, above the air vent11, there is an opening 13 (FIGS. 1 and 2) through which the elasticbeak 12 of the feed bar containing the longitudinal capillary groove 5projects to bear against the underside of the nib 3. The upper edge 23of the front part 1 of the fountain pen is slightly inclined towards thefountain pen axis so that the axial beak 12 of the feed bar 2 extendsslightly beyond the edge after having passed through the front part 1and bears with a slight elastic bias against the underside of the nib 3.This ensures that the longitudinal capillary groove 5 will maintaincontact with the nib and hence ensure a continuous feed of ink even whenmaximum pressure is applied to the nib.

The rear part of the feed bar 2 forms a heel 15 (FIGS. 1 and 9) throughwhich the main capillary groove 5, the two lateral capillaries 16 andthe air channel 17 extend into the ink reservoir 20. The heel 15,provided the ink reservoir 20 is suitably constructed, permits the samefront part of the fountain pen and the same feed bar to be used both forself-filling plunger type pens and for pens adapted to receive cartridgerefills. In the illustrated example the illustrated pen is of theself-filling plunger type in which the plunger 21 has a socket-shapedaxial recess roughly adapted to conform with the shape of the rear endof the heel 15. This arrangement permits the annular cavity surroundingthe heel 15 to be used a reserve ink container from which ink can bedrawn when the fountain pen has been emptied in the normal way and theplunger 21 is pushed forward. The forward movement of the plungerdisplaces the ink from the annular cavity and presses it through theheel 15 into the front part 1 of the pen and the ink pockets.

The nib 3 is fitted to the front part 1 of the fountain pen from theoutside. It is accurately shaped and held in lateral slits 14, as shownin FIG. 3. This permits retailers of fountain pens to replace nibs whenrequired without special difficulties.

During use of the pen, the ink from the ink reservoir 20 flows throughthe capillaries 16 and 5 to the underside of the nib. The flow of ink iscontrolled by the passage of air through the feed control channel 4which the ambient air can reach through the bore 11 and the channels 9and 24 (FIG. 8). Since the longitudinal capillary groove 5 communicateswith the ink pockets through the semicylindrical capillary gap 8, thecollecting pockets fill evenly and the intercepted volume of ink isproperly withdrawn or emptied into the ink chamber when the fountain penis held upright or when air pressure and temperature change. Theseparation of the air channel from the longitudinal capillary groove inthe front and middle portions of the feed bar, the complete enclosure ofthe longitudinal capillary groove, the baffle 10 in the air channel andthe transverse feed control channel all cooperate to prevent escape ofink upon shaking the pen and to satisfy the highest demands in thisrespect.

It is, of course, to be understood that the present invention is by nomeans, limited to the particular constrution shown in the drawings, butalso comprises any modifications within the scope of the invention.

What I claim is:

1. A fountain pen having an ink reservoir and a front portion with anib, a feed bar including: a feed control channel for communication withthe ink reservoir to conduct air and ink in opposite directions, alongitudinal capillary groove formed by crossbars and capillary groovedefining means for connecting the feed control channel at the topside ofthe fountain pen to the underside of the nib, an assembly of ink pocketsformed by fins separated by capillary slots and communicating with saidlongitudinal capillary groove and means forming a noncapillary ventingchamber in communication with the outside and with the ink pockets, theventing chamber extending from the ink feed bar underside longitudinallyto the ink-reservoir-side end of the ink pocket assembly and supplying adosage regulating path for venting access to the ink reservoir whichcommunicates with an enlargement of the longitudinal capillary grooveand including an air channel leading to said feed control channel, saidair channel comprising an inner section, a middle section and an outersection, said inner section establishing communication between said feedcontrol channel and said ink pockets while said middle section of saidair channel extends underneath said fins axially throughout the entirelength of said feed assembly diametrically opposite said longitudinalgroove, and the outer section of said air channel comprising a borecommunicating with the outside and being radially offset from the middlesection of said air channel, the inner end of said bore being covered byone of said fins facing the bore in close juxtapostion thereto andcreating a kind of labyrinth, said feed bar also being provided withsemi cylindrical capillary gap means simultaneously establish ing fulllength communication between space of said ink catching pockets and saidlongitudinal capillary groove with which the feed bar bore and fountainpen front portion communicates.

2. A fountain pen having a feed bar according to claim 1, for insertioninto a fountain pen the front part of which has an opening, whichincludes an elastic tongue containing said longitudinal capillary grooveand projecting beyond said ink pocket assembly, said feed bar beinginsertable into said fountain pen so that said elastic tongue iselastically biased to bear against the underside of the nib and theupper side of said elastic tongue forms an acute angle with respect tonib bed location upon removal of said nib.

3. A fountain pen having a feed bar according to claim 1, in which saidfeed control channel is exclusively a transverse channel in a shaftportion of the feed bar, the feed control channel progressivelyextending peripherally from the inner section of the air channel to thelongitudinal capillary groove.

4. A fountain pen having a feed bar according to claim 1, in which itsrear end has a stud projecting into the ink reservoir for collectivelydefining a ring-shaped ink reservoir space between said stud andcylindrical wall reservoir formation and for cooperation with thesocketed end of a plunger therein to form supplementary ink catchingpockets capable of being emptied by shifting said plunger thoughotherwise the ink content therein is unusable for writing purposes.

5. A fountain pen having a feed bar according to claim 3, in which asingle feed control channel exclusively extending in transversedirection is provided at ink reservoir end location at a level lyingadjoining the last catching pocket.

6. A fountain pen having a feed bar according to claim 1, in which theouter end of the middle section of the air channel is a radially offsetoutwardly extending bore, and a fin serving as a baflle with closejuxtaposition spacing for labyrinth uncovering of an inner end of saidoffset outwardly extending bore.

References Cited UNITED STATES PATENTS 2,756,722 7/1956 Lamy 401-226FOREIGN PATENTS 907,750 3/ 1954 Germany. 350,570 l/ 1961 Switzerland.

LAWRENCE CHARLES, Primary Examiner

